Paper wrappers for smoking articles are disclosed in U.S. Pat. Nos. 2,673,565; 2,801,636; 3,744,496; 3,931,824; 4,129,134; 4,225,636; 4,231,377; 4,420,002; 4,433,697; 4,450,847; 4,622,983; 4,805,644; 4,881,557; 4,911,184; 4,915,118; 4,924,888; 4,941,485; 4,941,486; 4,984,589; 4,998,542; 4,998,543; 5,060,674; 5,092,306; 5,105,837; 5,103,844; 5,121,759; 5,131,416; 5,220,930; 5,228,463; 5,450,862; and 5,540,242, the disclosures of which are hereby incorporated by reference.
Of the above patents, the '674 patent discloses adding monoammonium phosphate to cigarette paper as a burn modifier; the '543 patent discloses adding monoammonium phosphate to cigarette paper to reduce streaking of the outer paper due to condensation on the inside paper following puffs; the '837 patent discloses adding halides, sulfates and phosphates such as ammonium chloride, magnesium chloride, magnesium sulfate, mono-ammonium sulfate and disodium phosphate to cigarette paper as burn retardants; and the '242 patent discloses adding alginates including ammonium alginate to cigarette paper as a film forming additive to reduce sidestream smoke.
U.S. Pat. No. 2,815,760 discloses a tobacco smoke filter having an ion exchange material which chemically reacts with and retains carbonyl compounds such as aldehydes in the filter. U.S. Pat. No. 3,685,070 discloses a tobacco smoke filter containing the lipid soluble antioxidant N,N'-diphenyl-p-phenylenediamine (DDPD) for lowering the cytotoxic substances in the smoke. U.S. Pat. No. 3,716,063 discloses a tobacco smoke filter which selectively removes volatile aldehydes, the filter being a porous particulate material such as alumina impregnated with buffered poly(alkyleneimines). U.S. Pat. No. 3,878,853 discloses a cigarette filter containing a cationic component and a high molecular weight polyamine component for removal of ciliatoxic compounds from tobacco smoke.
While there have been proposals in the prior art for modifications to cigarette filters to remove aldehydes from mainstream smoke, such proposals lead away from the present invention wherein the wrapper of a tobacco smoking article is effective in reducing the content of gaseous components in mainstream smoke.